In order to be easy to carry, existing scooters, frog kick scooters, tri scooters and swing scooters are additionally provided with a handlebar folding unit. Chinese Patent 201020523385.7 discloses a “Folding Unit for Scooters”. In this technical solution, a folding unit for scooters is characterized in that a connecting base formed by two mutually matched casings is provided at a lower end of a handlebar; a positioning tab is provided within the cavity of the connecting base; a concave pit is provided on one side of the positioning tab; the connecting base in front of the concave pit is provided with an elongated through hole; a lower portion of the connecting base is in pin connection and rotatable fit with a fixed seat; a lower end of the positioning tab is protruded out of the bottom of the connecting base to be in elastic socket-fit with the fixed seat; and a positioning button and a spring are provided within the cavity of the connecting base, the fixed seat is provided with a positioning hole matched with the positioning button, and the positioning button and the positioning hole are in elastic socket-fit with each other. The folding unit for scooters features in simple and compact structure. However, it has the following deficiencies. First, since the positioning tab is provided within the cavity of the connecting base, when in use, one must put a finger into the cavity to pull the positioning tab and then rotate the handlebar to complete folding or unfolding of the positioning unit, which is very inconvenient. Second, the scooter has no safety mechanism, and its safety performance is thus unsatisfactory when in use. Third, a connecting base formed by two mutually matched casings is required to be customized for the scooter, resulting in complex structure and high manufacturing cost.